The food industry has struggled to develop effective antimicrobial treatments for controlling the growth of foodborne pathogens on uncured meat products (particularly poultry products) that are cost and time efficient and acceptable to consumers. The United States Department of Agriculture (USDA) and its Food Safety and Inspection Service (FSIS) have issued regulations related to controlling Listeria monocytogenes, a food borne pathogen that can cause potentially fatal infections in newborns, the elderly and other immuno-compromised individuals.
Specifically, as discussed in 9 C.F.R. §430.1 and 430.4 (Jan. 1, 2005), L. monocytogenes can contaminate Ready-To-Eat (RTE) products that are exposed to the environment after they have undergone lethality treatment. In order to enhance product safety and verify sanitary processing conditions, companies that produce post-lethality exposed RTE products must comply with requirements that are set forth in certain Alternatives, Alternative 1 is the most stringent alternative. Alternatives 1 and 2 are discussed in further detail for reference.
Alternative 1 involves a post-lethality treatment (which may involve an antimicrobial agent) that reduces or eliminates microorganisms on the product. Alternative 1 also involves use of an antimicrobial agent or process that suppresses or limits the growth of L. monocytogenes over time. An antimicrobial agent is a substance in or added to an RTE product that reduces or eliminates a microorganism, including pathogens such as L. monocytogenes, or that suppresses or limits growth of pathogens throughout the shelf life of the product. Examples antimicrobial agents include acidified calcium sulfate (ACS), potassium lactate and sodium diacetate.
Under the regulations set forth in 9 C.F.R. §430, dated Jun. 6, 2003 and Food Safety and Inspection Services (FSIS) directives, Alternative 1 required that the initial reduction of pathogens in or on the meat product be greater than 1 log after an antimicrobial agent was applied or injected into the food item and, in addition, less than 2 log growth after the initial reduction, e.g., during shelf storage. Under current regulations set forth in 9 C.F.R. §430, dated Jan. 1, 2005 and FSIS directives, the current Alternative 1 standard is more stringent than the prior Alternative 1 standard and requires greater than 2 log initial reduction (compared to greater than 1 log reduction), and less than 1 log growth (compared to less than 2 log growth). Thus, the current Alternative 1 increased the level of initial pathogen reduction, and allows for less pathogen growth over time compared to the prior Alternative 1 standard.
Alternative 2 involves use of either a post-lethality treatment (which may involve an antimicrobial agent) that reduces or eliminates microorganisms on the product, or an antimicrobial agent or process that suppresses or limits growth of L. monocytogenes. Alternative 2 can be satisfied with either post-lethality treatment or the use of an antimicrobial agent, whereas Alternative 1 requires both of these treatments. Alternative 2 requires that the reduction of pathogens in or on the meat product be reduced by greater than 1 log reduction, or less than 2 log growth after the initial reduction, e.g., during shelf storage.
ACS has been recognized and approved as an antimicrobial agent for treating RTE meat products. ACS is useful for killing L. monocytogenes on food surfaces, and for preventing or limiting growth of L. monocytogenes after an initial ACS application, e.g., during shelf storage or shipping. Two known methods for applying ACS to meat products are dipping and spraying meat products.
Known dip methods involve dipping meat products into a bath of ACS for a certain amount of time. With known dip methods, however, the ACS may not sufficiently purge liquids on the exterior surface of the produce and penetrate into the meat products. Instead, the ACS may be applied to only the outer surface. Thus, while the entire meat product may be covered by ACS when dipped, the amount of ACS that penetrates the meat product may be negligible or may be insufficient for purposes of satisfying Alternatives 1 and 2. Higher concentrations of ACS may, therefore, be required with dip methods, which can negatively impact the taste of the product.
Known spray methods involve spraying meat products with ACS. Known spray methods, however, have not been implemented in a cost efficient manner while satisfying Alternatives 1 and 2. For example, the extent to which the ACS penetrates the meat products is limited. Further, known spray systems may not apply ACS to all or substantially all of the meat product surfaces, thus causing more potential difficulties with satisfying the Alternatives. Consequently, known spray systems may not apply sufficient quantities of ACS to meat product surfaces, leave certain surfaces untreated, and provide only limited ACS penetration through the outer surface of the meat product.
Accordingly, there exists a need for a system and method that applies ACS to all or substantially all of the surfaces of a meat product to reduce surface pathogens, and to ensure that sufficient quantities of ACS penetrate meat products to prevent future pathogen growth to satisfy USDA and FSIS regulations. There is also a need for a system and method that can achieve these results in a large-scale commercial environment in a time and cost efficient manner. There is also a need for a method that effectively applies ACS to meat products while maintaining the taste of meat products. Embodiments of the invention fulfill these unmet needs.